This invention relates to a depth-measuring periodontal probe and recording apparatus of the type used by dentists to measure the depth of the pocket between the gum and the tooth. The depth of the pocket also known as gingeval sulcus, is measured from the margin of the gum (the top of the gum) to the epithelial attachment (the point where the gum attaches to the tooth), which forms the bottom of the pocket. Measurement of pocket depth is a primary method for detecting periodontal (gum) disease. Peridontal disease is commonly known as pyorrhea. It has been estimated that most adult tooth loss in the United States today is the result of peridontal disease, not dental caries (cavities). As peridontal disease progresses, the pockets become larger and are filled with bacteria and pus, and in time, destruction of the tissue attachment to the teeth and destruction of the supporting bone structure occurs. Periodontal disease is usually painless, site specific and goes through periods of exacerbation and remission, therefore, an improved, easy to use and record producing periodontal probe and apparatus is a much needed tool in the dental field.
It is common knowledge that early detection and periodic measurements at several locations, as many as six per tooth, is necessary to determine if the gingival sulcus (pocket) is enlarging and how fast. There are many instruments used to measure and record the depth of the pocket such as the Ward Periodontal probe, U.S. Pat. No. 3,058,225, which has a handle with a protruding sleeve and flexible probe tip that connects directly to a mechanical indicator or indirectly to an electric current indication device located on the probe handle. There are disadvantages with this type of probe. The sleeve is long and difficult to keep clean. Blood and other body fluids can create deposits inside the sleeve, which can interfere with the smooth movement of the probe tip. These deposits tend to become hardened and more of a problem following heating precedures of sterilization. Therefore, it is important that any sleeve be kept short, open and easy to clean. Since the dentist makes all measurements by taking his eyes off the tip and observing the indicator, time is lost to observe a measurement. Since there are as many as six measurements per tooth, and the normal mouth has as many as thirty-two teeth, the time lost in taking as many as 192 separate measurements is considerable. Another disadvantage is that probing force is not controlled.
Another prior art periodontal probe is disclosed in Grenfell et al, U.S. Pat. No. 3,943,914, which includes a remote recording console, electrically connected to this probe to provide a permanent record of the depth of the gingival sulci around the particular tooth. The major disadvantage with this type of probe is the long sleeve, which is difficult to keep clean. Probing force is not controlled, which is another disadvantage.
There are commercially available periodontal probes, for example, The Vine Valley Research Corp., sells a unit which sounds a "beep" when a preset probing force is reached. The unit, developed by Dr. Ronald N. Yeaple, U.S. Pat. No. 4,340,069, does not electronically measure pocket depth, only probing pressure. Also, the Oratronics, Inc., sells a unit which consists of a tip which slides within a plastic sleeve, and digital readout and a printer. The long plastic sleeve is difficult to keep clean and tip movement can become restricted.
A published articles in The Journal of Periodontology, 1980, Vol. 51, No. 5, pp. 298-300, "A Periodontal probe that Measures to One Tenth Millimeter", by S. G. Detsch, discusses a probe with a mechanical readout on the handle. It utilized a caliper attached to a probe tip. The probe tip slides within a curved sleeve. This probe does not control force and does not provide electronic readout. The curved sleeve is long and difficult to keep clean.
An article by U. van der Velden and J. K. de Vries that appeared in The Journal of Clinical Periodontology, 1978, Vol. 5, pp. 188-197, entitled. "Introduction to a New Periodontal Probe: The Pressure Probe", discusses the use of air pressure to extend the probe tip which slides within a sleeve. During probing, the tip will intrude from the position of maximum extension at a force determined by the present pressure, until the metal sleeve contacts the gum margin. The pocket depth is read from a millimeter scale on the handle. The probe does not have a remote readout and the use of air pressure requires a machine unit that is expensive to produce. The sleeve is long and difficult to keep clean.
Lautenschlager et al, in U.S. Pat. No. 4,203,223, described a periodontal probe, which provided a constant force. The sleeve was relatively short, which is advantageous for cleaning. However, there was no provision for electronic measurement. Pocket depths must be read visually as with common probes.
Recently, Ackerman et al, in U.S. Pat. No. 4,665,621 described a periodontal probe with frictional means for limiting probing force, electronic measurement and a microcomputer for analyzing and displaying the data. This probe has a long, curved sleeve, which is difficult to clean. The curved portion of the sleeve adds friction during movement. The probe tip is extended into the gingival sulcus by pressing a control sleeve, which is not convenient to use because it is difficult to simultaneously slide a sleeve and position the probe tip in the gingival sulcus.
A serious handicap of clinical studies and clinical treatment has been the lack of an objective means of measuring progression of periodontal disease. One of the methods periodontists use to diagnose and assess the progression of the disease is tissue attachment level and bone loss by the measure of periodontal pocket depth. Pocket depth is measured with a probe and because there is not a controlled, standardized way of probing, it is only a crude measurement. There is a critical need for a reliable technique for making rapid, accurate measurements in a standardized fashion. The periodontal probe of this invention overcomes the objections of the prior art and is an improvement over standard probes in that it maintains a constant probing force, can record pocket depths distal to posterior teeth accurately (remote readout), provides electronic measurements for computer recording of the data, and is easy to keep clean and operating smoothly without frictional forces coming from a gummed up, dirty sleeve.